1. Field of the Invention
The present invention relates to new insecticidal secreted proteins (“ISPs”) isolated from a bacterial strain, preferably a Brevibacillus species strain, most preferably a Brevibacillus laterosporus species strain which are insecticidal when ingested in combination with an ISP-complimentary protein such as another ISP protein of this invention, and to DNA sequences encoding such proteins. These proteins are useful to prevent or minimize insect damage, particularly of corn rootworms, to plants in a field.
The present invention also relates to plants, particularly corn plants, that are rendered insecticidal, preferably to coleopteran insects, particularly to Diabrotica spp., Leptinotarsa spp. and Anthonomus species insects, by the expression of the ISP proteins of this invention in cells of said plants.
The present invention also relates to a method for controlling damage by Diabrotica spp., Leptinotarsa spp. or Anthonomus species insects, preferably Diabrotica spp. insect pests, particularly corn rootworms, by having the ISP proteins of the invention, particularly the proteins with the amino acid sequence of any one of SEQ ID NO: 2, 4, 8 or 10, or insecticidally-effective fragments thereof, ingested by said insects.
2. Description of the Prior Art
Some of the most destructive pests are found among the Diabroticine beetles. In North America, the three important species of corn rootworms, Diabrotica virgifera (the Western corn rootworm), Diabrotica barberi (the Northern corn rootworm) and Diabrotica undecimpunctata howardi (the Southern corn rootworm) are considered to be the most expensive insect pests to control (Metcalf, 1986, Foreword in “Methods for the Study of Pest Diabrotica”, pp. vii-xv, eds. Krysan, J. L. and Miller, T. A., Springer-Verlag, New York). Diabrotica virgifera and Diabrotica barberi are considered the most serious insect pests of corn in the major corn-producing states of the United States and Canada (Levine and Oloumi-Sadeghi, 1991, Annu. Rev. Entomol. 36, 229-55). The larvae feed on the roots and thus cause direct damage to corn growth and corn yields. Costs for soil insecticides to control larval damage to the root systems of corn and aerial sprays to reduce beetle damage to corn silks, when combined with crop losses, can approach one billion dollars annually (Metcalf, 1986, supra). Recently, in some US states it was discovered that the crop rotation program of planting soybeans after corn lost its effect as corn rootworms have adapted to this situation.
Bacterial strains and/or genes with toxicity to corn rootworm have been described in U.S. Pat. Nos. 6,023,013; 6,015,553; 6,001,637; 5,906,818; and 5,645,831. Also, PCT publications WO 00/09697, WO 99/57282, WO 98/18932, WO 97/40162, and WO 00/26378 relate to toxins and genes obtainable from Bacillus or other bacterial spp., some of which are described to have toxicity to corn rootworm. WO 98/44137, WO 94/21795 and WO 96/10083 relate to pesticidal Bacillus strains, characterized by pesticidal proteins and auxiliary proteins produced during vegetative growth, some of which are described to have toxicity to corn rootworm. U.S. Pat. No. 5,055,293 describes a method to control corn rootworms by inoculating soil with parasporal-inclusion forming species of Bacillus laterosporus. 
Orlova et al. (1998, Applied Environmental Microbiol. 64, 2723) showed insecticidal activity to mosquitoes associated with protein crystals in crystal-forming strains of Bacillus laterosporus. 